1 2 static char help[] = "Scatters from a parallel vector to a sequential vector.\n\ 3 Tests where the local part of the scatter is a copy.\n\n"; 4 5 #include <petscvec.h> 6 7 int main(int argc,char **argv) 8 { 9 PetscMPIInt size,rank; 10 PetscInt n = 5,i,*blks,bs = 1,m = 2; 11 PetscScalar value; 12 Vec x,y; 13 IS is1,is2; 14 VecScatter ctx = 0; 15 PetscViewer sviewer; 16 17 PetscFunctionBeginUser; 18 PetscCall(PetscInitialize(&argc,&argv,(char*)0,help)); 19 20 PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 21 PetscCall(PetscOptionsGetInt(NULL,NULL,"-bs",&bs,NULL)); 22 23 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 24 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 25 26 /* create two vectors */ 27 PetscCall(VecCreate(PETSC_COMM_WORLD,&x)); 28 PetscCall(VecSetSizes(x,PETSC_DECIDE,size*bs*n)); 29 PetscCall(VecSetFromOptions(x)); 30 31 /* create two index sets */ 32 if (rank < size-1) m = n + 2; 33 else m = n; 34 35 PetscCall(PetscMalloc1(m,&blks)); 36 blks[0] = n*rank; 37 for (i=1; i<m; i++) blks[i] = blks[i-1] + 1; 38 PetscCall(ISCreateBlock(PETSC_COMM_SELF,bs,m,blks,PETSC_COPY_VALUES,&is1)); 39 PetscCall(PetscFree(blks)); 40 41 PetscCall(VecCreateSeq(PETSC_COMM_SELF,bs*m,&y)); 42 PetscCall(ISCreateStride(PETSC_COMM_SELF,bs*m,0,1,&is2)); 43 44 /* each processor inserts the entire vector */ 45 /* this is redundant but tests assembly */ 46 for (i=0; i<bs*n*size; i++) { 47 value = (PetscScalar) i; 48 PetscCall(VecSetValues(x,1,&i,&value,INSERT_VALUES)); 49 } 50 PetscCall(VecAssemblyBegin(x)); 51 PetscCall(VecAssemblyEnd(x)); 52 PetscCall(VecView(x,PETSC_VIEWER_STDOUT_WORLD)); 53 54 PetscCall(VecScatterCreate(x,is1,y,is2,&ctx)); 55 PetscCall(VecScatterBegin(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD)); 56 PetscCall(VecScatterEnd(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD)); 57 58 PetscCall(PetscViewerASCIIPushSynchronized(PETSC_VIEWER_STDOUT_WORLD)); 59 PetscCall(PetscViewerASCIISynchronizedPrintf(PETSC_VIEWER_STDOUT_WORLD,"----\n")); 60 PetscCall(PetscViewerGetSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&sviewer)); 61 PetscCall(VecView(y,sviewer)); fflush(stdout); 62 PetscCall(PetscViewerRestoreSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&sviewer)); 63 PetscCall(PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD)); 64 PetscCall(PetscViewerASCIIPopSynchronized(PETSC_VIEWER_STDOUT_WORLD)); 65 66 PetscCall(VecScatterDestroy(&ctx)); 67 68 PetscCall(VecDestroy(&x)); 69 PetscCall(VecDestroy(&y)); 70 PetscCall(ISDestroy(&is1)); 71 PetscCall(ISDestroy(&is2)); 72 73 PetscCall(PetscFinalize()); 74 return 0; 75 } 76 77 /*TEST 78 79 testset: 80 nsize: 3 81 output_file: output/ex24_1.out 82 filter: grep -v " type:" 83 test: 84 suffix: standard 85 args: -vec_type standard 86 test: 87 requires: cuda 88 suffix: cuda 89 args: -vec_type cuda 90 test: 91 requires: viennacl 92 suffix: viennacl 93 args: -vec_type viennacl 94 95 TEST*/ 96